Rule: max-line-length

Requires lines to be under a certain max length.

Rationale

Limiting the length of a line of code improves code readability. It also makes comparing code side-by-side easier and improves compatibility with various editors, IDEs, and diff viewers.

Config

It can take one argument, which can be any of the following:

  • integer indicating maximum length of lines.
  • object with keys:
    • limit - number < 0 defining max line length
    • ignore-pattern - string defining ignore pattern for this rule, being parsed by new RegExp(). For example:
      • // pattern will ignore all in-line comments.
      • ^import pattern will ignore all import statements.
      • ^export {(.*?)} pattern will ignore all multiple export statements.
      • class [a-zA-Z]+ implements pattern will ignore all class declarations implementing interfaces.
      • ^import |^export {(.*?)}|class [a-zA-Z]+ implements |// pattern will ignore all the cases listed above.
Config examples
"max-line-length": [true, 120]
"max-line-length": [true, {"limit": 120, "ignore-pattern": "^import |^export {(.*?)}"}]
Schema
{
  "type": "array",
  "items": {
    "oneOf": [
      {
        "type": "number"
      },
      {
        "type": "object",
        "properties": {
          "limit": {
            "type": "number"
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "additionalProperties": false
      }
    ]
  },
  "minLength": 1,
  "maxLength": 2
}